This grant from the Organic Dynamics Program supports the continuing work of Professor Edward M. Arnett at Duke University. Heats of heterolysis, homolysis and electron transfer for a wide spectrum of organic compounds will be determined using calorimetry and electrochemical techniques. The heterolytic bond strengths will be determined from heats of reactions of carbon electrophiles (e.g., carbenium ions, carbonyl functions, Michael acceptors, activated aromatics) with a wide range of nucleophiles (e.g., carbanions, ylides, alkoxides, thiolates, nitroanions). These experiments will be used to compare directly heterolytic and homolytic cleavages of covalent bonds. This work will allow the building of a basic thermodynamic framework by which many processes for making and breaking bonds to carbon can be compared directly. %%% A thermodynamic framework will be built for bonds between carbon and hetero atoms. Calorimetry and electrochemical techniques are the experimental methods of choice. By measuring bond dissociation energies and the heats of reaction between ionic species, a common scale can be determined for a large spectrum of bonds. The data to be obtained from this research will form an important thermodynamic database that is to provide fundamental insight in the bond making/breaking processes of all organic reactions.
